scars of reality
How much more difficult would the walkthrough become without fortifying strategically important points?
I think that without fortifying, the walkthrough would become significantly more difficult. Not to the point where it would be completely impossible, but it would be much harder. At the very least, because you would lose a lot of resources. The AI, considering their numbers, would spread out like cockroaches and start taking over castles one after another, and simultaneously in different parts of the map. It would be quite problematic to keep up with them and manage to reclaim everything.
And I think the author also intended for players to fortify. Otherwise, what would be the point of making such small coastal lines in the starting part of the map? Some of the islands, even quite large ones, are blocked by just two or three trenches. There are no such narrow coastal lines anywhere else on the map. Moreover, he clearly gives more than enough time before the first AI attacks. I assume this is also for that purpose.
